Method of making castings of composite metals



Feb. 27, w23. I 21,4%678 C.'T.VV|L1(S METHOD OF MAKING CASTINGS OF COMPOSITE METALS Filed Dec. l1, 1920 f 7 Ill////////////"" il" Patented i923.,

CHARLES T. l/VILKS, OF CLNTON, IKGESSOUREI.

Application iiled'ieccniber 11, 1920,

To all 'whom at may concern.'

it known ,that l, CHARLES T. lll/inns, citizen of the lJnited States, residing at Clinton, ltleiny County, Missouri, lh ave .invented a new and useful Method onlalring {lasting/'s of Composite Metals, of which the following is a specification.

This invention relates to improvements in method of making castings of composite metal.

lleretofore in practice attempts have been made to fuse bronze with iron, semi-steel or steel to maire a composite casting havino' section of the bronze integrally united with a section of the iron, semi-steel or steel. Such efforts have been unsuccessful in forining castings having a perfect union between the two metals.e By continued experiment l have developed a method whereby a casting may be formed having a layer or sec- 'tion of bronze integrally united with a layer or section of iron, semi-steel or steel.

The object of this invention, therefore, is the production of armethod for forming composite castings from bronze and iron, semi-steel or steel integrally united.

The invention may be better understood by the following description taken in connection with the drawing, which is submitted for illustrative purposes only, which drawing discloses a vertical section through a mold utilized in thepractice of the method or process. y

The mold in which the castings are formed is of the usual type compris-ing a drag l and a cope 2. moldl cavity 3 is formed in the sand l carried by the drag. 1Biunningthrough the sand body 5 of the cope and into the mold cavity, preferably at opposite ends, are duplicate gate or riser passages 6 and 7. Vl`he passages 6 and 7 are arranged to enter the mold cavity at a level corresponding to the upper surface of the layer of bronze.

ihe method in which the casting is poured consists in providing a molten mixture including copper, lead and tin mixed substantially in the proportion of eighty, ten and ten. The molten mixture is poured into either of the openings 6 and 7, the mold being filled to the level of the inlet of the pouring passage. The quantity of molten niet-al required to lill the mold cavity to pre-determined level is calculated in ad- 5.5 vance, so the pouring ladle contains just sufficient metal to raise the level in the Serial No. 429,864.

mold cavity to the throat of the pouring cavity.

After the'bronze or copper alloy has been poured a suilicient interval of time is allowed for it to partially solidify or come to a semi-molten state in the mold. The iron, semi-steel or steel mixture is then poured from the other pouring passage into the mold, the first pouring passage constituting a riser passage for the metal.

lt has been found by experinient that in order to accomplish satisfactory results it is necessary that tue iron, semi-steel or steel shall include at least one per cent mangaese, and also that no Zinc shall be included in the copper alloy.

r` `he casting poured as above described, results in a perfect union along a substantially well'delined line which, however, is somewhat irregular due to the irregular upper surface of the first pouring of the metal. lt is important that the first layer be allowed to partially solidify in order to prevent it from becoming mixed with the second layer.

The general theory of the process is that the bronze mixture having a lower melting point than the iron and being allowed to cool will maintain its conformation throughout the body when the iron, semi-steel or steel mixture is poured upon it, and that the higher melting point of the molten iron, semi-steel or steel will suiliciently raise the temperature of the surface of the lower layer to cause it to intermix for a sufficient depth with the second pouring, so that the two will unite forming a substantially perfect union between the two layers.

rllhe sequence in which the layer of molten iron, semi-steel or steel and the layer of the bronze mixture is poured may be reversed, although it is preferable that the bronze mixture be poured first. An interval of time is allowed between the pouring of the layer of iron, semi-steel or steel to allow the same to cool slightly before the bronze is poured so that the bronze will not go through the first layer.

l claim: G5

l. The method of forming composite castings composed of a copper alloy free from zine; and iron, semi-steel or steel, which consists in pouring a molten copper alloy into a mold to form a stratum in the bottom of the mold; permitting said stratum to come to a semi-molten state; and then pouring into @rip the mold onto the semi-molten stratum a quantity of molten iron, semi-steel or steel to increase the heat of the contiguous copper alloy and to form undulations in the same to `form a stratum having a thickness from the top of the rst stratum to the top Wall of the mold.

2. The method of forming a composite casting, composed of a copper alloy free romzinc; and iron, semi-steel or steel, Which consists in pouring a quantity of the molten copper alloy free from zinc and including copper, ilcad and tin, into a mold to form a stratum Jin the bottom of the mold; permittingsaid stratum to come to a semi-molten state; and then pouring into the mould onto the first stratum a quantity omolten iron, Semi-steel or steel, including at least one per cent manganese, to increase the heat of the contiguous copper alloy and to form undulations in the same to form a stratum having a thickness from the top of the first stratum to the opposite Wall of the mold.

k3. The method oi 'forming a composite casting composed of a copper alloy free from zinc; and iron, semi-steel or steel, Which'consists in pouring the molten copper alloy free from zinc, and composed-olil copper, lead and tin mixed substantially in the proportions of eighty per cent copper, ten per cent lead, and ten per cent tin, into a mold to form a stratum in the bottom of the mold; causing said stratum to come to asemi-molten state; and then pouring into the mold onto the lirst stratum a quantity of molten iron, semisteel or steel including at least one per centV manganese7 to increase the heat of the contiguous copper alloy and to form indulations in the sameto form a stratum having a thickness from the top oi the first stratu to the opposite Wall of the mold.

4. rlhe method of ,forming a .composite casting composedov a copper alloy free from zinc; and iron, semi-steel or steel7 containing manganese, which `consists in pouring a quantityof one oi the molten Ymetals into the mold to form a lower stratum; partially cooling` the lower stratum r`toa semi-molten stategand 'then pouring into the mold onto the iirst stratum a yquantity .of the other metals to increase the'heat of the contiguous copper alloyand to form undulations in the same and to iorm an upper stratum eX- tending tothe upper Wall of the mold.

CHAS. T. WILKS. 

